Clarke American Selects ATG to Power New E-Commerce Site.

CAMBRIDGE, Mass. -- ATG (Art Technology Group, NASDAQ: ARTG) the software provider behind the most consistent and relevant marketing, commerce, and customer service experiences, today announced that Clarke American, Inc., the leading provider of checks and check-related products, contact center services, Internet and direct response marketing solutions for the financial services industry, has selected ATG Commerce and ATG Content Administration to power its new e-commerce and online marketing environment, called Customer ConnectionPoint.

Each year, the company produces more than 10 billion personal and business checks in a variety of formats for more than 4,000 banks, credit unions and other financial institutions nationwide. The company has more than 3,200 associates and a national network of electronically linked production facilities and customer service centers located throughout the United States.

ATG Commerce is the recognized leader in BtoC (business-to-consumer) commerce, according to recent reports published by analyst firms Forrester Research and Gartner, Inc.; and ATG Content Administration is considered the most comprehensive Web content management solution designed to support personalized Web sites.

"Clarke American shares ATG's vision that providing the most relevant, effective, and consistent online experiences will motivate more, higher-value purchases from both new and returning online customers," said Cliff Conneighton, senior vice president of marketing, ATG. "We are looking forward to working with Clarke American to deliver all the e-commerce, personalization, and content/catalog management capabilities that will power their new site.

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) makes the software that the world's most customer-conscious companies use to create a more relevant and consistent customer experience, throughout the marketing, commerce, and service lifecycle, and across the Web, e-mail, call center, and mobile channels. Offering an alternative to the traditional silo-based approach to customer-facing applications, ATG Wisdom(TM) is the company's strategy for delivering a seamless, more compelling, and mutually valuable experience to each customer and segment. The company fulfills this strategy by providing fully integrated best-of-breed product suites installed on-premise or delivered on-demand. ATG's solutions power over 600 major brands, including A&E Networks, Airbus, American Airlines, American Eagle Outfitters, Best Buy, Boeing, Cingular Wireless, DirecTV, France Telecom, Friends Provident, Hewlett-Packard, Hotels.com, Hyatt Hotels, HSBC, InterContinental Hotels Group, Kingfisher, Louis Vuitton, Merrill Lynch, Neiman Marcus, Philips, Procter & Gamble, Symantec, T-Mobile, Target, USAA, US Army, US Navy, Warner Music, and Wells Fargo. The company is headquartered in Cambridge, Massachusetts, with additional locations throughout North America, Europe, and Asia. For more information about ATG, please visit www.atg.com.

(c) 2005 Art Technology Group, Inc. ATG and Art Technology Group are registered trademarks of Art Technology Group, Inc. All other product names, service marks, and trademarks mentioned herein are trademarks of their respective owners.

This press release contains forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks and uncertainties that may cause ATG's actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by such forward-looking statements. Important risk factors affecting ATG's business generally may be found in their periodic reports and registration statements filed with the Securities and Exchange Commission at www.sec.gov . Risk factors related to the subject matter of this press release include the possibility that the ATG product deployment will not be successful, on time or significantly enhance the user's Internet experience or will not increase customer revenue across brands; that those customers leveraging ATG won't have the opportunity to increase revenue and decrease future costs; the need to adapt to rapid changes so products do not become obsolete; the possibility of errors in ATG's software products; the possibility that the solution will not make customer implementations faster or more flexible or permit the customer to meet its customer-facing or infrastructure requirements; that the ATG product will not continue to be integrated with third party applications servers or will not support all Web services enabled systems; that ATG's product strategy may change in the future; and the risks and costs of intellectual property litigation. ATG undertakes no obligation to update any of the forward-looking statements after the date of this press release.